Simultaneous Spectrophotometric determination of Metal Ions in Aqueous Solutions Using a Simple Spectra Ratio Method

Abstract

A simple spectrophotometric method was developed for the simultaneous determination of Ni, Co, Pd, Cu, Zn, and Fe without the need for any prior separation steps. The method is based on the differences of absorbance ratios in two and/or three wavelengths. The mathematical model of the method was first presented, then applied to the modelled data with adding random noise, finally applied to the spectrophotometric data of ions in binary and ternary liquid mixtures. The spectrophotometric analysis based on the complexation reaction of these cations with 1-(2-pyridylazo)-2-naphthol (PAN). Under the optimum condition, the calibration curve was linear over the concentration ranges from 0.1 to 5 μg/L with the RSDs under 4.21%. The results indicated that the proposed method is relatively simple and rapid for the analysis of binary and ternary mixtures with a satisfactory precision and accuracy.